Nursing Elites

1. What is the primary function of the respiratory system?

• A. Maintain body temperature
• B. Deliver oxygen to the bloodstream and remove carbon dioxide
• C. Produce antibodies for the immune system
• D. Break down food molecules for energy

Correct answer: B

Rationale: The primary function of the respiratory system is to deliver oxygen to the bloodstream and remove carbon dioxide. This process occurs through breathing, where oxygen is inhaled into the lungs and then transferred to the bloodstream, while carbon dioxide is removed from the bloodstream and exhaled out of the body. Maintaining body temperature (A), producing antibodies for the immune system (C), and breaking down food molecules for energy (D) are functions of other systems in the body, not the respiratory system. Therefore, the correct answer is B.

2. Which structure in the respiratory system is responsible for gas exchange?

• A. Trachea
• B. Alveoli
• C. Bronchi
• D. Diaphragm

Correct answer: B

Rationale: The alveoli in the lungs are responsible for gas exchange. Alveoli have a rich blood supply and thin walls, enabling the exchange of oxygen and carbon dioxide. Oxygen diffuses into the blood from the alveoli, while carbon dioxide diffuses out. The trachea functions as an air passage, bronchi are the main airways into the lungs, and the diaphragm is the primary muscle involved in breathing by aiding in lung expansion and contraction, but they are not directly responsible for gas exchange like the alveoli.

3. A ball is thrown horizontally off a cliff. Which of the following forces is responsible for its downward motion?

• A. The force of throwing
• B. Normal force from the air
• C. Tension force from the string (if used)
• D. Gravitational force

Correct answer: D

Rationale: The gravitational force is responsible for the downward motion of the ball. When the ball is thrown horizontally off a cliff, the only force acting on it in the vertical direction is the force of gravity, which pulls the ball downward towards the ground. The other forces mentioned (force of throwing, normal force from the air, tension force from the string) do not contribute to the ball's downward motion in this scenario. The force of throwing initiates the horizontal motion, the normal force from the air opposes the ball's motion through air resistance, and tension force from the string would only be relevant if a string were attached to the ball. Therefore, gravitational force is the primary force responsible for the ball's downward motion in this situation.

4. What is the final stage of both mitosis and meiosis?

• A. Interphase
• B. Telophase
• C. Cytokinesis
• D. G1 phase

Correct answer: B

Rationale: - Interphase (option A) is not the final stage of mitosis or meiosis; it is the phase before cell division where the cell prepares for division by growing and replicating its DNA. - Telophase (option B) is the final stage of both mitosis and meiosis. During telophase, the separated chromosomes reach opposite poles of the cell, the nuclear membrane reforms around each set of chromosomes, and the chromosomes begin to decondense. - Cytokinesis (option C) is the process of dividing the cytoplasm to form two separate daughter cells. While it occurs after telophase, it is not considered the final stage of mitosis or meiosis. - G1 phase (option D) is the first gap phase in the cell cycle, occurring before DNA replication. It is not the final stage of mitosis or meiosis.

5. Which of the following correctly identifies a difference between the primary and secondary immune response?

• A. In the secondary response, macrophages migrate to the lymph nodes to present the foreign microorganism to helper T lymphocytes.
• B. The humoral immunity that characterizes the primary response is coordinated by B lymphocytes.
• C. The primary response is quicker and more powerful than the secondary response.
• D. Suppressor T cells are activated in the secondary response to prevent an overactive immune response.

Correct answer: C

Rationale: The correct answer is C. The primary immune response is slower and less powerful compared to the secondary immune response. During the primary response, immune cells encounter the antigen for the first time, necessitating the activation and proliferation of specific immune cells. In contrast, the secondary response benefits from memory cells that quickly recognize the antigen, enabling a faster and more potent immune response. Choices A, B, and D are incorrect. While macrophages play a role in presenting antigens to T cells, this is not a defining difference between primary and secondary responses. Humoral immunity involves B lymphocytes in both primary and secondary responses, so it does not differentiate the two. Suppressor T cells primarily function to regulate the immune response but are not a key factor distinguishing primary from secondary responses.

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